If we had an award for most improved in the SSD space, it would have to go to Samsung. When we first encountered Samsung MLC drives a few years ago they were pretty bad. Prices were high and performance was low. Samsung offered no end-user upgradable firmware for those early drives either, although that was eventually rectified. The first Samsung MLC SSDs were reliable, they just weren't worth the money when you had much better options from companies like Intel.

Samsung had all of the right pieces for success however. Like Intel, Samsung made its own NAND, controller and wrote its own firmware. Unlike Intel, Samsung stuck to the vertically integrated formula.

I remember arguing with Samsung engineers a few years ago about the importance of random IO performance compared to sequential speed. I remember feeling like they were making the same mistake that all SSD makers were making back then: heavily prioritizing sequential IO when it was a failure to deliver good random IO performance as well that really hurt SSD adoption. Although the first Samsung SSDs weren't very good, they got better over time. While the first generation couldn't be recommended, the Samsung SSD 470 could. It still wasn't our favorite drive, but it finally brought performance up to a reasonable level. Last year's 830 release showed us that Samsung woke up. Today, Samsung is adding two new members to the family: the Samsung SSD 840 and the 840 Pro. The former is the first productized consumer SSD to use Samsung's 21nm 3-bit-per-cell MLC (aka TLC) NAND, while the latter is Samsung's new flagship drive using 21nm 2bpc MLC NAND.

Unfortunately we don't have samples of the unique TLC SSD 840, just the MLC 840 Pro. Despite the use of TLC NAND, Samsung claims the vanilla 840 should offer similar performance to the current 830. Samsung also claims that endurance should be reasonable for consumer workloads.

The 840 Pro should be tangibly faster than the 830 thanks to a new controller, new firmware and new NAND:

Samsung SSD 840 Pro vs 830

Samsung SSD 830 (256,512GB)

Samsung SSD 840 Pro (256,512GB)

Sequential Read

520MB/s

540MB/s

Sequential Write

400MB/s

450MB/s

Random Read

80K IOPS

100K IOPS

Random Write

36K IOPS

78K IOPS

Active Power Use

0.24W

0.068W

Idle Power Use

0.14W

0.042W

While the 830 used Samsung's 27nm MLC NAND, the 840 Pro uses Samsung's latest 21nm MLC NAND. The move to 21nm will eventually drive NAND pricing lower, although today Samsung expects price parity between the TLC equipped 840 and the old MLC 830. The 840 Pro should sell for a 25 - 30% premium over the current 830.

Samsung SSD 840 Pro Pricing

64GB

128GB

256GB

512GB

Samsung SSD 840 Pro

$99.99

$149.99

$269.99

$599.99

The move to 21nm is also coupled with a move to a 400Mbps Toggle 2.0 NAND interface. Block and page sizes remain the same for 2bpc MLC 21nm NAND, and maximum capacity per die is still 8GB. Although beyond the scope of this article, 3bpc TLC 21nm NAND sees 50% slower program/erase times compared to the 2bpc MLC 21nm NAND.

Both the 840 and 840 Pro use Samsung's 4th generation SSD controller. Samsung's MAX controller was used in the SSD 470, its successor, the MBX controller, wasn't used in retail drives, while MCX debuted in the 830 and MDX is in the 840/840 Pro. The basic architecture of the controller hasn't changed. Internally there are three ARM9 cores now running at 300MHz. Update: Samsung originally listed ARM9 cores but has since told us that there are three ARM Cortex R4s inside of the new MDX controller.

The MDX controller features a hardware AES-256 encryption engine that's managed using a system BIOS password like most other drives in this class.

The MDX controller is paired with 512MB of LPDDR2-1066 in the Samsung SSD 840 Pro, doubling up the DRAM used in the 830 as well as increasing bandwidth to DRAM by 33%:

SSD DRAM Size Comparison

Drive

Controller

DRAM Size

DRAM Speed

Corsair Neutron GTX

LAMD LM87800

256MB

DDR2-800

Crucial m4

Marvell 88SS9174

256MB

DDR3-667

Intel SSD 320

Intel X25-M G3

64MB

SDR-166

Intel SSD 520

SandForce SF-2281

0MB

-

OCZ Vertex 4

Indilinx Everest 2

512MB/1GB

DDR3-800

Samsung SSD 830

Samsung MCX

256MB

DDR2-800

Samsung SSD 840 Pro

Samsung MDX

512MB

LPDDR2-1066

The 840 Pro will be available in 64 - 512GB capacities. Although the controller supports up to 1TB of NAND, Samsung believes that the ultra-high-density NAND required to hit 1TB is too cost prohibitive at this point. Spare area is set at around 7% by default, although users will be able to adjust it via Samsung's SSD Magician utility. The vanilla 840 on the other hand will boast more spare area (likely to help manage endurance on the TLC NAND) and will launch at 120GB, 250GB and 500GB capacities as a result.

The 256GB SSD 840 Pro features 8 x 32GB NAND devices on the front of the PCB and nothing on the back

The 840 comes with a 3 year warranty compared to a 5 year warranty on the 840 Pro.

The 840 Pro drops the brushed aluminum look of the 830 for slightly more modern, flat black styling. The drives will be available in a 2.5" 7mm form factor, similar to the 830.

Samsung SSD 840 Pro (top) vs. Samsung SSD 830 (bottom)

Both drives will be available on October 15th, however in advance of the release Samsung provided us with a beta sample for review. We were only able to get a 256GB 840 Pro initially but we've already asked Samsung for additional capacities. The other bad news is after running through our client test suite and preparing the drive for a run through our enterprise suite, our pre-production sample died. This isn't the first time we've had an SSD die during our test process, pretty much every company has seen a failure during one of our reviews, but despite Samsung's excellent track record even it isn't immune from early issues. These drives are a few weeks away from retail and Samsung will be getting our sample back this week to figure out what went wrong.

Update: My replacement 840 Pro also died, I have shipped both drives back to Samsung and are waiting for their analysis of the failures.

Post Your Comment

96 Comments

While the 840 Pro kicks ass, I wonder if the 3bpc 840 is going to have less endurance while offering the same performance as the previous gen 830 drive... If that's the case buy them up while they're on sale in the next few months before they run out. Unless another SSD maker comes out with a drive that tops the 840 Pro, it's going to command a premium price per gb for some time.Reply

I ended up buying a Samsung 830 about a year ago and I have absolutely loved it, fast performance plus rock stable. I might consider grabbing one of these when the price comes down a bit.

I was wondering if say Samsung or any other SSD manufacturer didn't care about power consumption as much, and say clocked those 3 cortex A9 cores @ 700Mhz instead of 300, would 4k random performance increase significantly? Or are these SSDs mainly limited by firmware still even at 300Mhz, so increasing the clockspeed won't have much impact. What about if they added a 4th core instead of increase clock speed?Reply

... to replace my aging Intel 320 series (300GB). Just wondering if it will make a tangible (in my eyes) difference in day to day use, since I don't care about benchmarking. Maybe it will be better to pick up a cheaper 830 which is proven to be reliable... either way, the Intel will go to my PS3 since I'm pretty sure it will be nearly useless to sell in the used market.Reply

I'm kind of in a similar boat, kind of wanting to upgrade my desktop's 160GB 320 with a drive that's faster and a bit more spacious. I had paired it with a 64GB Samsung 830 to free up the space used by the memory swap file, but I probably wouldn't do that if I got a larger drive.

I could probably use the 64GB drive for my Steam folder, but I'd still be left with the 160 GB 320, as well as another 40 GB 320...it's like, what would I use those drives for? I guess I could hang onto them for when I get around to building a Linux box...Reply

-- I had paired it with a 64GB Samsung 830 to free up the space used by the memory swap file

I've always wondered: a swap file gets hammered, so when partitioning a drive with some swap and some user file system, does leveling only happen *within* the user defined partition? Or does the controller (or varying by controller) level across devices without regard to partitions?

I had thought about that as well, when I decided to move the swap file; I wish Windows would let you move the hibernate image file too, for the same reason. That being said, though...I'm just not that worried about it, anymore. I don't think swap files or even hibernating your computer are going to do your SSD in prematurely.Reply

Really? 'Cause I have to say I never felt that the 320 quite lived up to all the hype about SSDs. And the sequential read times of the 840 should be significantly higher than those of the 320, right? Meaning that your boot times, application load times, level load times, etc. should be noticeably faster?Reply